Ten Sleep was an American Indian rest stop, so called because it was 10 days' travel, or “10 sleeps,” from Fort Laramie (southeast),^[14] Yellowstone National Park (west-northwest)^{[citation needed]}, and the Indian Agency on the Stillwater River in Montana (northwest)^{[citation needed]}. There are numerous archeological sites throughout the area, with frequent discoveries of artifacts such as arrowheads, pictographs and petroglyphs.

Ten Sleep was also the site of the Spring Creek Raid, one of the last feuds of the West's Sheep and Cattlemen's War. It was there in March 1909 that cattlemen attacked sheep herders and their flock, killing three men and shooting hundreds of the sheep. Caught and convicted, this was the end of major conflict, although it was many years before the two livestock growers' groups resolved their differences.

 Archaeology/paleontology

Rich in prehistory, fossil specimens of dinosaurs, plants and sea-life are prolific throughout the region. One such area, Big Cedar Ridge, is open to the public for exploration and collection for personal use.^[15]

 Geology

The yellowish-gray to white sandstone which forms much of Ten Sleep Canyon is named the Tensleep Formation (Pennsylvanian), and dominates much of the western slope of the Bighorn Mountains. The prominent red sandstone, such as Signal Cliff just west of Ten Sleep, as well as the dirt hills all along the west slope of the Bighorn Mountains are of the Chugwater Formation (Triassic). Above Chugwater, follows the marine Jurassic Sundance Formation and the terrestrial Late Jurassic Morrison Formation^[16] with dinosaurs. Called the "Painted Desert" or "Colored Hills" by locals, the Cloverly Formation is finely granuled sandstone, clay and "gumbo". The Cloverly formations contains bands of various mineral colors ranging from greens and grays to red and violets, and are closely associated with strata containing dinosaur fossils. Numerous signs along U.S. 16 from Buffalo, through Ten Sleep and west to Worland identify the various geologic formations and their millennia.

 Demographics

2020 census

The 2020 United States census counted 246 people, 120 households, and 76 families in Ten Sleep.^[19][20] The population density was 1,344.3 per square mile (519.0/km²). There were 146 housing units at an average density of 797.8 per square mile (308.0/km²).^[20][21] The racial makeup was 97.56% (240) white or European American (97.15% non-Hispanic white), 0.0% (0) black or African-American, 0.81% (2) Native American or Alaska Native, 0.0% (0) Asian, 0.0% (0) Pacific Islander or Native Hawaiian, 0.41% (1) from other races, and 1.22% (3) from two or more races.^[22] Hispanic or Latino of any race was 0.81% (2) of the population.^[23]

Of the 120 households, 28.3% had children under the age of 18; 47.5% were married couples living together; 24.2% had a female householder with no spouse or partner present. 30.8% of households consisted of individuals and 16.7% had someone living alone who was 65 years of age or older.^[20] The average household size was 1.9 and the average family size was 2.5.^[24] The percent of those with a bachelor’s degree or higher was estimated to be 20.3% of the population.^[25]

19.5% of the population was under the age of 18, 4.5% from 18 to 24, 18.7% from 25 to 44, 22.8% from 45 to 64, and 34.6% who were 65 years of age or older. The median age was 52.5 years. For every 100 females, there were 83.6 males.^[20] For every 100 females ages 18 and older, there were 83.3 males.^[20]

The 2016-2020 5-year American Community Survey estimates show that the median household income was $36,324 (with a margin of error of +/- $22,038) and the median family income was $66,786 (+/- $14,350).^[26] Males had a median income of $43,125 (+/- $31,607) versus $18,750 (+/- $12,426) for females. The median income for those above 16 years old was $25,000 (+/- $9,389).^[27] Approximately, 10.0% of families and 12.9% of the population were below the poverty line, including 39.5% of those under the age of 18 and 8.2% of those ages 65 or over.^[28][29]